There is a lot of value in being able to identify users, and starbucks 100% is constantly analyzing the gain they get from identifying users against the losses

There is a lot of value in being able to identify users, and starbucks 100% is constantly analyzing the gain they get from identifying users against the losses the incur from an increased bounce rate. (I work in adtech and am part of similar tests for similar brands) Almost certainly these tests do not take into account longterm affects on user's opinions on the brand, etc.